Hi, Callistemon are pruning group 8, which normally means minimal pruning, just cutting back any shoots that spoil the appearance of the shrub, but these can stand a hard prune, aand should be done immediately after flowering, Derek.

Because mine's in a pot, I prune immediately the flowers have died back - new growth appears beyond where the flowers are, and it tends to make for a tatty looking bush - new growth at the tip, a gap and then old growth beneath. Cut back to just below the bottom of the flower - best done a bit earlier, when fading flowers are still visible.

Thank you very much for your information.

Gail. x